NEW HAVEN, Conn. — Petra Kvitova’s final tuneup for the US Open ended with a 6-2, 6-1 loss to Shuai Zhang of China in the first round of the Connecticut Open Monday night.

Kvitova, a two-time Wimbledon champion and a three-time champion in New Haven, is just 4-4 on hard courts this season. The Czech player returned to the tour at the French Open in May after she was stabbed during a home invasion in December, leaving her dominant left hand seriously injured.

Zhang, ranked 29th, was playing her first match in the United States since April.

“I just arrived in New Haven last night, coming straight from China,” she said. “It’s a big change. It’s 12 hours’ time difference. Before the match I was still sleeping.”

Earlier Monday, Canadian Eugenie Bouchard breezed past higher-ranked American Lauren Davis 6-3, 6-1. Bouchard, a wild-card entry, next faces top-seeded Agnieszka Radwanska.

Bouchard, who reached a career-best No. 5 in the rankings in 2014, has struggled recently, slipping to 74th.

In other matches, Kirsten Flipkens of Belgium beat Lesia Tsurenko of Ukraine 6-2, 6-3, and Romania’s Ana Bogdan got past Russia’s Elena Vesnina, 7-5, 7-5.

The US Open begins Aug. 28.

Mirjana Lucic-Baroni of Croatia and Alize Cornet of France won first-round matches.

Cornet beat Yulia Putintseva of Kazakhstan 6-0, 6-0, and Lucic-Baroni overcame 11 double faults and held off Anett Kontaveit of Estonia 6-7, 7-6 (7-3), 6-3.

Azarenka withdraws from US Open

Two-time US Open runner-up Victoria Azarenka confirmed her withdrawal from the tournament on Monday amid a custody battle concerning her eight-month-old son.

Azarenka, who signaled last week she may miss the tournament rather than travel to New York without her son Leo, confirmed her withdrawal in a statement.

“I am sadly unable to compete in this year’s US Open due to my ongoing family situation that I am working through,” the Belarus star said.

“While I will dearly miss being in New York and playing in one of my favorite tournaments where I have enjoyed some of the best moments in my career, I am already looking forward to being back next year.”

The Belarusian reached the final in 2012 and 2013 where she was beaten by Serena Williams on both occasions.

The 28-year-old said last week she would skip Flushing Meadows rather than be separated from her baby.

It came after a Los Angeles judge presiding in her custody case with the boy’s father, Billy McKeague, said the child could not leave California until the matter had been resolved.

Azarenka, ranked 204 after a layoff while pregnant and after her son’s birth, played last month at Wimbledon, reaching the round of 16 before losing to second-ranked Simona Halep.

“Shortly after Wimbledon, Leo’s father and I separated and as we work to resolve some of the legal processes, the way things stand now is that the only way I can play in the US Open this year is if I leave Leo behind in California, which I’m not willing to do,” Azarenka said last week.

“I look forward to hopefully having positive developments soon so that this difficult situation can be resolved and I can get back to competing.

“No parent should have to decide between their child or their career.” — Agencies